title: Effects of risedronate on cortical and trabecular bone of the mandible in glucocorticoid-treated growing rats.
abstract: BACKGROUND
  This study was performed to estimate the effects of risedronate on mandibular bone density, bone structure, and bone metabolism in established glucocorticoid-induced osteoporosis in growing rats.
  
  
  METHODS
  The rats were given oral risedronate at 0, 0.5, or 1.0 mg per kilogram per day for 4 weeks after the administration of oral prednisolone at 30 mg per kilogram per 2 days for 6 weeks. Trabecular and cortical bone masses were analyzed by using peripheral quantitative computed tomography, and bone structure and bone formation were measured by using static and dynamic histomorphometry.
  
  
  RESULTS
  In trabecular bone, risedronate improved the prednisolone-induced decreases in bone cross-sectional area and bone mineral content. Risedronate increased bone density and also formed dense bone microarchitecture by reducing the bone turnover rate. In cortical bone, risedronate improved the prednisolone-induced decreases in bone cross-sectional area and bone mineral content without affecting bone density by increasing the mineralizing surface.
  
  
  CONCLUSIONS
  Risedronate improved prednisolone-induced retardation of trabecular and cortical bone growth, but the bone turnover in these 2 sites was regulated differently in the growing rat mandibles.
authors.affiliation: Division of Developmental Stomatognathic Function Science, Department of Growth and Development of Functions, Kyushu Dental College, Kitakyushu, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Fujita
authors.forename: Koji
authors.initials: K
authors.lastname: Watanabe
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Uchikanbori
authors.forename: Kenshi
authors.initials: K
authors.lastname: Maki
mesh_terms: D019412:Anatomy, Cross-Sectional; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D012968:Etidronic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D005938:Glucocorticoids / Q000009:adverse effects*; D008297:Male; D008334:Mandible / Q000187:drug effects* / Q000254:growth & development / Q000473:pathology; D008903:Minerals / Q000032:analysis; D009929:Organ Size / Q000187:drug effects; D010006:Osteoblasts / Q000187:drug effects / Q000473:pathology; D010012:Osteogenesis / Q000187:drug effects; D010024:Osteoporosis / Q000139:chemically induced / Q000503:physiopathology; D010521:Periosteum / Q000187:drug effects / Q000254:growth & development / Q000473:pathology; D011239:Prednisolone / Q000009:adverse effects*; D051381:Rats; D017208:Rats, Wistar; D000068296:Risedronic Acid; D013997:Time Factors; D014057:Tomography, X-Ray Computed
chemical_list: D050071:Bone Density Conservation Agents; D005938:Glucocorticoids; D008903:Minerals; D011239:Prednisolone; D000068296:Risedronic Acid; D012968:Etidronic Acid